Printing-pastes and process of producing same.



nnirun snares ranna JOHANN 'CARSTENS, F LEVERKUSEN, GERMANY, ASSIGNOR T0 FARBENTFABiPe-IIEN VORM. FRIEDR. BAYER- &. 00., OF ELBERFELD, GERMAN Y, A CORPORATION OF GE' J Patented Jan, 26 11915,

MANY. e

PRINTING-PASTES AND-PROCESS or PRODUCING SAME.

1,12 3% Specification of Letters Patent.

Ho Drawing.

' Printing-Tastes and-Processes of Produo,

are much more soluble.

ing Same, of which the following a specification The printing with vat dyestufis of the anthraquinone series has been hitherto carried out in such manner that the dye wasfixed on the fiber as leuco compound by steaming in the presence of a large quantity of caustic soda lye; the use of caustic soda lye, especially in large quantities suffers however from several disadvantages; e. g. the change (mercerization) of the cotton, fiber (see Laubers Handbuch ales Zeugdruclcs, Ergdnzungsbaml H, page 20, etc; Peters Fiirbereeitung (1911) page 740, etc.

I have now found that printing pastes can be produced from vat dyestufi's of the anthraquinone series. which can be printed without free alkali and that the above mentioned disadvantages can be avoided. This process consists in neutralizing the excess of alkali in the vat prepared with the aid of caustic alkalis with alkali-binding agents of a weak acid character such as sodium bicarbonate, potassium bicarbonate, bisulfite, aluminum acetate, aluminum hydrate, boric acid, organic acids etc. The resulting printing pastes yield as good results and in many cases even better results than can be obtained by the use of a printing paste containing free alkali in which these dyestufis This is all the more surprising as earlier attempts to overcome the difliculties arising from the use of free alkali by the use of printing pastes which had been prepared by simply mixing the dyestufi, reducing agent and sodium carbonate with the paste without previous solution have practically proved a failure and Application flied November 20, 1912. Serial No. H2525.

as this process can only duction of light shades.

In order to illustrate the invention more fully the following examples are given, the parts being by weight:

Ewample J.

of algol blue RG (paste) of glycerin of thickening (a. g. starch canth mucilage) of hydrosulfite of soda lye Be.

are well stirred together and heated to about 40 w. After the dyestud is dissolved of sodium bicarbonate of rongalite C powder are added.

he used for the pro- 150 gr. 3O

In using this paste cotton is printed with it, dried, steamed for 5 minutes in the mather platt, chromed in open width with an aqueous bichromate solution containing 10 grams of acetic acid and 3 grams of bichromate per liter of water, rinsed, soaped at the boil for 10 minutes and finished.

Example 2.

of algol blue RG (paste) of glycerin;

' alkali and In using the resulting paste the goods are printed and finished as above described.

E sample 3. 150 gr. of algol blue 3R (paste):

50 of soda lye 50 Be. 15 of hydrosulfite powder concentrated are well stirred together; after 1 the vat is formed it is adde to a mixture 0 605 of thickening 30 of gylcerin of potassium bicarbonate of rongalite C In using this paste it is printed on'silk and the goods finished as described in Example 1.

I claim 1. The process of making printing pastes which comprises dissolving vat dyes of the anthraquinone series with the aid of caustic alkali, neutralizing the excess of alkali with an alkali-binding agent of a weak acid character, and adding thickening and reducing agents at some stage of the process. 2. The process of making printing pastes which comprises dissolving vat dyes of the anthraquinone series with the aid of caustic a reducing agent, neutralizing the excess of alkali with an alkali-binding agent of a weak acid character, and adding thickening agents at some stage of the process. a

3. The process of making printing pastes which comprises dissolving vat dyes of the anthraquinone series with the aid of caustic alkali and a reducing agent, neutralizing the excess of alkali with an alkali-binding agent of a weak acid character, and adding thickening agents and a further amount of reducing agent at some stage of the process. 4. The process of making printing pastes which comprises dissolving vat dyes of the anthraquinone series with the aid of caustic alkali and a reducing agent, neutralizing the excess of alkali with an alkali-binding agent of a weak acid character, adding a further amount of reducing agent, and adding thickening agents at some stage of the process.

5. In the art of making printing pastes from vat dyes of the anthraquinone series,

the process which comprises neutralizing with an alkali-binding agent of a weak acid character, the free alkali present in a vat prepared with the aid of caustic alkali and a reducing agent.

6. In the art of making printing pastes, from vat dyes of the anthraquinone series, the process which comprises neutralizing with an alkali-bicarbonate, the free alkali present-in a vat prepared with the aid of caustic alkali and'a reducing agent.

7 The process'pf making printing pastes which comprises dissolving vat dyes of the anthraquinone series with the alkali, neutralizing the excess of alkali with an alkali-binding agent of a weak acid char acter, and adding thickening agents and sulfoxylate as reducing agent at some stage of the process;

8. The process of making printing pastes which comprises dissolving vat dyes of the anthraquinone series with the aid of caustic alkali and hydrosulfite, neutralizing the excess ening agents at some stage of the process.

9. The process of making printing pastes which comprises dissolving vat dyes of the anthraquinone series with the aid of caustic alkali and hydrosulfite, cess of alkali with an alkali-binding agent of a weak acid character, ening agents and a further amount of: reducing agen at some stage of the process.

10. The process of making printing pastes which comprises dissolving vat dyes of the anthraquinone series with the aid of caustic alkali and hydrosulfite, neutralizing the excess of alkali with an alkali-binding agent of a weak acid character, adding a further amount of reducing agent, thickening agents at some stage of the rocess. v I

11. Printing pastes comprising a vat dye of tho anthraquinone series in a reduced condition in which paste the free alkali has been neutralized with an alkali-binding agent of a weak acid character, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

J OIIANN CARSTENS. [L- s] Witnesses.

HELEN Norm, ALBERT Nurnn.

aid of caustic of alkali with an alkali-binding agent of a weak acid character, and adding thickneutralizing the ex- I and adding tlnckand adding I 

